A satellite positioning receiver includes a local oscillator, a front-end circuit with having an analog mixer, a number of signal processing channel circuits, and a processing circuit. The satellite positioning receiver performs a method that includes (i) acquiring a first satellite using a first frequency search space that spans both uncertainties due to the first satellite's orbit and uncertainties due to the clock bias or a time rate of change of the bias; and (ii) using the bias or the time derivative of the bias determined during the acquisition of the first satellite, acquiring a second satellite using a second frequency search space that spans substantially only uncertainties due to the second satellite's orbit.
Legal claims defining the scope of protection, as filed with the USPTO.
2. The satellite positioning system receiver of claim 1, wherein the local oscillator comprises a temperature-compensated crystal oscillator.
3. The satellite positioning system receiver of claim 1, wherein the acquiring the first satellite provides a measurement of a distance from the first satellite which, along with satellite ephemeris data, is used to solve system state variables that include (i) an estimate of the receiver's position and (ii) an estimate of the clock bias or the time rate of change of the clock bias.
4. The satellite positioning system receiver of claim 3, wherein the system variables further comprise an estimate of the receiver's velocity.
5. The satellite positioning system receiver of claim 3, wherein code delays and doppler frequencies are determined in the signal processing channel circuits for a plurality of satellites.
6. The satellite positioning system receiver of claim 5, wherein solving the system state variables is achieved using a Kalman filter.
7. The satellite positioning system receiver of claim 6, wherein estimates of the clock bias, and atmospheric compensation factors are input variables to the Kalman filter.
8. The satellite positioning system receiver of claim 6, wherein the Kalman filter is based on a zero-mean Gaussian noise.
9. The satellite positioning system receiver of claim 6, wherein the estimate of the time derivative of the clock bias is updated in the Kalman filter using a linear function of one or more of the doppler frequencies.
11. The method of claim 10, wherein the local oscillator comprises a temperature-compensated crystal oscillator.
12. The method of claim 11, wherein acquiring the first satellite provides a measurement of a distance from the first satellite which, along with satellite ephemeris data, is used to solve system state variables that include (i) an estimate of the receiver's position and (ii) an estimate of the clock bias or the time rate of change of the clock bias.
13. The method of claim 12, wherein the system state variables further comprise an estimate of the receiver's velocity.
14. The method of claim 12, wherein the code delays and doppler frequencies are determined in the signal processing channel circuits for a plurality of satellites.
15. The method of claim 14, wherein solving the system state variables is achieved using a Kalman filter.
16. The method of claim 15, wherein estimates of the clock bias, and atmospheric compensation factors are input variables to the Kalman filter.
17. The method of claim 15, wherein the Kalman filter is based on a zero-mean Gaussian noise.
18. The method of claim 15, wherein the estimate of the time derivative of the clock bias is updated in the Kalman filter using a linear function of one or more of the doppler frequencies.
19. The satellite positioning system receiver of claim 1, wherein the dispatch circuit assigns the sections of the IF signal according to a category scheme that is based on an estimated code delay.
20. The satellite positioning system receiver of claim 19, wherein the category scheme is further based on an estimated doppler frequency.
21. The method of claim 10, wherein the sections of the IF signal are assigned according to a category scheme that is based on an estimated code delay.
22. The method of claim 21, wherein the category scheme is further based on an estimated doppler frequency.
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May 8, 2020
February 28, 2023
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